// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_CURSOR_H_
#define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_CURSOR_H_

#include <stdint.h>

#include <memory>
#include <string>

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "content/browser/indexed_db/indexed_db_backing_store.h"
#include "content/browser/indexed_db/indexed_db_database.h"
#include "content/browser/indexed_db/indexed_db_transaction.h"
#include "content/common/indexed_db/indexed_db_key_range.h"
#include "third_party/WebKit/public/platform/modules/indexeddb/WebIDBTypes.h"

namespace content {

class CONTENT_EXPORT IndexedDBCursor {
public:
    IndexedDBCursor(std::unique_ptr<IndexedDBBackingStore::Cursor> cursor,
        indexed_db::CursorType cursor_type,
        blink::WebIDBTaskType task_type,
        IndexedDBTransaction* transaction);
    ~IndexedDBCursor();

    void Advance(uint32_t count, scoped_refptr<IndexedDBCallbacks> callbacks);
    void Continue(std::unique_ptr<IndexedDBKey> key,
        std::unique_ptr<IndexedDBKey> primary_key,
        scoped_refptr<IndexedDBCallbacks> callbacks);
    void PrefetchContinue(int number_to_fetch,
        scoped_refptr<IndexedDBCallbacks> callbacks);
    leveldb::Status PrefetchReset(int used_prefetches, int unused_prefetches);

    const IndexedDBKey& key() const { return cursor_->key(); }
    const IndexedDBKey& primary_key() const { return cursor_->primary_key(); }
    IndexedDBValue* Value() const
    {
        return (cursor_type_ == indexed_db::CURSOR_KEY_ONLY) ? NULL
                                                             : cursor_->value();
    }

    void RemoveCursorFromTransaction();
    void Close();

    leveldb::Status CursorIterationOperation(
        std::unique_ptr<IndexedDBKey> key,
        std::unique_ptr<IndexedDBKey> primary_key,
        scoped_refptr<IndexedDBCallbacks> callbacks,
        IndexedDBTransaction* transaction);
    leveldb::Status CursorAdvanceOperation(
        uint32_t count,
        scoped_refptr<IndexedDBCallbacks> callbacks,
        IndexedDBTransaction* transaction);
    leveldb::Status CursorPrefetchIterationOperation(
        int number_to_fetch,
        scoped_refptr<IndexedDBCallbacks> callbacks,
        IndexedDBTransaction* transaction);

private:
    blink::WebIDBTaskType task_type_;
    indexed_db::CursorType cursor_type_;

    // We rely on the transaction calling Close() to clear this.
    IndexedDBTransaction* transaction_;

    // Must be destroyed before transaction_.
    std::unique_ptr<IndexedDBBackingStore::Cursor> cursor_;
    // Must be destroyed before transaction_.
    std::unique_ptr<IndexedDBBackingStore::Cursor> saved_cursor_;

    bool closed_;

    base::WeakPtrFactory<IndexedDBCursor> ptr_factory_;

    DISALLOW_COPY_AND_ASSIGN(IndexedDBCursor);
};

} // namespace content

#endif // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_CURSOR_H_
